Top: Bootstrapped cumulative distribution of grid-place cell coherence scores during replay (blue). Shaded areas shows 1SD of the bootstrap. Black line shows coherence scores based on a grid cell ratemap shuffle (random linear shifts of each grid cell ratemap). The x-axis show the grid-place cell coherence scores and the y-axis the proportion of events. Inset: difference between the data and shuffle distributions. Bottom: same as top except black line is derived randomly shifting the spike times of grid cells from the event. Coherence scores in the data distribution were significantly higher than those obtained from the two shuffling procedures (Spatial shuffle: p < 0.0001, Temporal shuffle: p < 0.0001, AUC test).